Mesoscale Precipitation Discussion 1096
NWS Weather Prediction Center College Park MD
417 AM EDT Thu Aug 20 2026

Areas affected...southeastern Missouri, western/central Kentucky,
western/Middle Tennessee, and far southern Illinois

Concerning...Heavy rainfall...Flash flooding likely

Valid 200817Z - 201417Z

Summary...A mature convective complex remains capable of areas of
backbuilding and training. Flash flood potential continues.

Discussion...Radar mosaic imagery depicts a lead MCS from near
Bowling Green, KY to near Dickson and Dyersburg, TN. Additional
convection continues to backbuild near the Paducah and Cape
Girardeau, MO areas. Much of the convection continues to develop
in response to a southwesterly low-level jet over northeastern AR,
which was maintaining areas of 2000 J/kg MLCAPE on the western
sides of the convection. Low-level convergence was also maximized
an the northeastern side of this LLJ axis from southeast MO into
western TN. 1.9+ inch PW values and upstream mid-level lapse
rates near 7C/km continue to foster strong updrafts as well.
Areas of flash flooding remain possible, with the greatest
near-term threat focused across Cape Girardeau, Paducah, and
surrounding areas that are currently experiencing their second to
third round of heavy rainfall tonight. Spots of 1 inch/hr rain
rates are continuing to foster FFG exceedance in the areas.

Additional backbuilding is expected over at least the next 2-3
hours as the aforementioned AR LLJ veers and eventually weakens.
Westerly, unstable low-level flow will continue to provide a risk
of backbuilding convection especially across western/Middle TN.
Ground conditions are comparatively less sensitive in most areas
(drier antecedent conditions, 2+ inch/hr FFG thresholds),
suggesting that any flash flood risk may be tied to urban and/or
sensitive spots and may be more isolated in nature compared to
MO/KY although if backbuilding can be sustained across
western/Middle TN for multiple hours, the flash flood threat will
increase. The degree/extent of backbuilding and heavy rainfall
duration is a bit uncertain though.

Cook

ATTN...WFO...HUN...JKL...LMK...LSX...MEG...MRX...OHX...PAH...

ATTN...RFC...MSR...ORN...TIR...NWC...

LAT...LON 37908889 37778719 37218547 36458456 35328574
35068869 35308979 36529050 37719027